1. Field of the Invention
The invention relates to a brushless DC motor structure.
2. Description of the Related Art
Conventionally, a brushless DC motor structure includes a motor body and a controller. The motor body includes a stator module, a rotor module, an axis of rotation, a front end cover, a casing, and a rear end cover. The front end cover and the rear end cover are mounted at two ends of the casing. The stator module and the rotor module are mounted inside the casing. The controller includes a box, a control circuit board mounted inside the box, and a box cover. The motor body and the controller are usually connected together with air vents disposed on top of the casing or a cast aluminum piece is employed for the controller's box to increase heat dispersion of power electronic components.
However, this kind of heat dispersion method is far from meeting the actual operating requirements of motors with the following disadvantages: 1) dust and rain water are likely to enter the motor through the air vents to cause motor failure and it is harmful for the running motors because heat dispersion effect is not ideal and operating temperature is relatively high; and 2) since the controllers generally have an enclosed structure, if only a cast aluminum piece works to disperse heat, the heat dispersion effect will not be as perfect as expected, often causing high temperature and motor failure.